polyaniline-cdse quantum dot nanostructure: characterization and properties

This research focuses on the synthesis of cadmium selenide quantum dots (cdse qds)-polyaniline (pani) nanocomposites. cdse qds were prepared by co-precipitation, and the polymerization process was carried out in the presence of qds to form an entangled nanocomposite. structural analysis of the sample revealed the formation of the main pani peaks along with an amorphous qds. chemical analysis confirmed the successful polymerization of pani and the formation of qd nanoparticles. the thermal behavior of pani samples with and without qds showed similar weight loss steps with less weight loss in the presence of pani, indicating increased thermal stability of the nanocomposite. the microstructure of pani showed an entangled, coil-like nanorod morphology. due to this cross-linked structure and the polymerization process, qds formed as amorphous particles with a uniform distribution within this ordered structure. structural and microstructural studies emphasized the presence of nacl impurity. the optical behavior of cdse qds synthesized at different temperatures from 70 to 100 °c showed that increasing the temperature shifts the emission to lower energy regions. the emission spectrum of the composite sample showed that the blue emission peak at around 420 nm is due to the π-π* electronic transition in polyaniline. with increasing the qd concentration to 10 % by weight relative to polyaniline, the formation of green emission spectrum of qds due to the electronic transition between these two luminescent centers reduced its intensity. these results indicate that due to the proper entanglement, the obtained product can be a suitable candidate for electroluminescent applications.